The present invention relates to an agricultural ground-working apparatus. More particularly, this invention concerns a cultivator.
A cultivator typically comprises a frame which is secured to the back of a tractor or other prime mover, usually at the three-point hitch thereof. A plurality of tines or similar ground-penetrating tools extend downwardly from this frame. As the frame is pulled along the ground in a normal direction of travel by the tractor the ground-penetrating tines work the soil, loosening and aerating it.
The ground-penetrating tools or tines of the cultivator are often mounted rigidly on the frame of the cultivator. Thus, whenever a solid object is struck by one of the tines, the entire frame will often rise up so that the one tine can clear the object it has struck, thereby leaving an unworked area of the field. The advantage of such rigid mounting of the tines is that it is possible to produce the cultivator at low cost.
It has been suggested to mount each of the tines pivotally on the frame and provide biasing means in the form of a spring for urging each time forwardly into a position extending generally perpendicular to the frame. Should such a tine be pulled against an obstacle it is therefore possible for it to pivot backwardly from its normal forward position, moving over the obstacle with only minor upward deflection of the frame carrying the tines. Such an arrangement has proven in practice to be unsatisfactory in that the springiness of the tines makes pulling the device through the ground quite difficult. Furthermore, when not perfectly set some of the tines invariably dig into the ground somewhat less than the others so that the cultivation is uneven or irregular.